The S70 uses a tension spring instead of a torsion spring for the tensioner pulley on the pump drive belt. This new system reduces maintenance and increases uptime according to Bobcat. Anyone know if the newer setup works for the 463? The spring broke on my 463 today. I was able to limp it back to the shop so I'm dead in the snow for now. In the process of pulling the engine because there's no way to change the spring without doing so. As far as I can tell anyway. No parts in stock and warehouse closed for the Holidays. $20 for the belt, $25 for the spring and $90 for the pulley???? Parts couter quote. Sound right?? Looking at later next week.
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I probably should have drove to the dealer before ordering the parts. Would like to see how the enhanced tension spring setup is installed on the S70 vs the torsion spring on the old 463's. Since they both use basically the same engine and chassis. Anybody know where I can find an illustration of the S70 setup?? I've looked high and low on the net, can't find anything. Thanks! Steve
This is what they're doing with the larger units I guess. Maybe something similiar for the S70? http://i306.photobucket.com/albums/nn277/skayser2/getImage_zps57f8ffcf.jpg
Thanks, Steve
OldMachinist
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S70 drive belt setup
All the Bobcat parts illustrations are online when you click the parts catalog here. http://www.bobcat.com/partsandservice/genuine_parts
Oh, I see....Thanks! I will keep that link. Looks like it would need the cover, flywheel, belt, pulley etc. to make the swap even if it would work on the ealier 463. Appreciate your time. On my way to the dealer to make sure they ordered to right stuff. Pulling the engine appears to be a PIA. Snow coming but that will have to wait at least a week or so. Thanks again. Steve
OldMachinist
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Engine and pump assembly come out together. Not too bad of a job. I can pull it on my 453 in 2 hrs. or less. I do it every couple of years to clean the debris out that accumulates under and behind the assembly. Previous owner never cleaned it out and I had to replace several steel hydraulic lines that rusted out from sitting in damp crud.
2 hrs....not bad then. It sure looks worse though huh. I have the manual so I'll get it eventually. I checked, they ordered the right stuff. Thanks again and have a great Christmas!!! Steve
Finally found enough time to get the engine out. Managed to get it out without a hoist. Might be a different story getting it back in. Only thing I destroyed was the oil sending unit so far. As noted the torsion spring end broke off resulting in no spring pressure at the tension pulley. No parts till next week.
Heres a pic of the broken spring. Belt, pulley and shaft bearings were in pretty good shape for being nine years old. Don't suppose it would be beneficial to fab up an arm and adjusting bolt on the shaft to replace the torsion spring if it lasted that long. http://i306.photobucket.com/albums/nn277/skayser2/engineout2002_zpsf9f3710d.jpg
One other thing. Don't remember why I installed the frost plug heater in the head. Dealer may have advised me to install it there. I was alittle reluctant because of the possible danger in creating a hot spot in the #3 cylinder/chamber. I don't leave it plugged in for long periods and haven't had problems yet. Anyone installed it in the block? You can see two frost plugs now that the engine is out. One below the fuel pump and one at the #3 cylinder. Would be a great time to make it right if there was room in the block water jacket. Curious if anyone has installed one there before I remove one of em to check?? Thanks! http://i306.photobucket.com/albums/nn277/skayser2/engineout2007_zpscc5bb35b.jpg
Forget that, I noticed the frost plugs are different size down low...wouldn't fit anyway unless a smaller frost plug was made.
After more inspection of the tensioner pulley parts, I can understand why Bobcat is on their 3rd tensioner design for this unit. They used a bronze bushing to support the inside end of the shaft instead of a bearing as used at the outside end. It appears that the bronze bushing, which is designed to float, froze up in the housing and had not turned for quite some time. It eventually started wearing the bushing and shaft. The bushing is worn to the point that the shaft has started wearing into the support bracket mounted to the engine. I assume this lead to unnecessary fatigue on the spring end and eventual spring failure. Spraying "Store N Lube" periodically might have prevented the failure. http://i306.photobucket.com/albums/nn277/skayser2/Tensionspringfailure001_zps43fb325e.jpg
http://i306.photobucket.com/albums/nn277/skayser2/Tensionspringfailure002_zps2efc12a5.jpg
OldMachinist, you being familiar with the tension setups on these small machines, do you think a fabricated solid pulley adjustment would work/last? Maybe would be too hard on the belt, pump bearing etc? What do ya think? Parts still aren't here, maybe have too much time to think about this. The bracket ($110), spring ($20) and back bushing ($2) are shot for sure. Ordered the pulley ($90) because I'm there already. Was going to replace the outside bearing also but at $170 don't think so. I'll try and get some new grease in the bearing somehow. Bobcat is crazy proud of their parts, huh.
Wouldn't ever do that, just over thinking. Done allot of timing belts changes on cars over the years where the tensioner pulley, after belt adjustment, remains stationary. They don't see the constant load changes as the skid steer pump does though.
OldMachinist
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Those prices are ridiculous. I don't want jinx myself here but I've had very little trouble with my idler. I replaced the pulley a while back when I had the engine out but I used a off the shelf pulley. Seems like that bearing was just a standard 2 bolt flange mounted bearing.
Yeah, don't know what they see in their bearing for the idler. Bought and test fit a Sealmaster SFT-10 flange bearing from my local machine shop. Wasn't an exact fit but after beltsanding an 1/8" for overall thickness and drilling bolt holes to 7/16 makes it works perfect." Also had to grind a notch to allow the spring tang to pass through the pump mounting bracket. Overall it's a much bigger and better bearing. Greaseable also and at fraction of what Bobcat wants for theirs ($40). http://i306.photobucket.com/albums/nn277/skayser2/tensionerbearing001_zps09fb3bb7.jpg
To be able to replace the idler pulley, do I have to remove the engine? Or can I move it to the side enough to be able to replace the pulley? I have the variety of bracket with a bolt on it and there is not enough room to remove the pulley around the bolt. I don't have a hoist or a lot of space to work on it. I am inspired on how clean you keep the inside of your bobcat. I'll be cleaning mine in this process.
Dave, sounds like your setup is the same as mine. If you pulled all four mount bolts and pushed it over you might be able to get it off. The trick would be getting the stick wedged in between the bracket and pump mount bolt to hold the spring tension as shown in the manual. One might slide the motor over first to see if the pulley could be removed without R&R the engine then maybe hold against the spring somehow from above(turn-buckle/short chain?? or maybe just a pry-bar from below?? Wish I had tried that before I removed the engine, just for future reference. As mentioned earlier, don't buy the Bobcat pulley. Your local machine shop should be able to fix you up for half the cost. Maybe more than half. Hope that helps! Good luck Steve
All 4 bolts removed and I can't move the engine enough to get the new pulley on. The oil fill line prevents me from moving it enough to the left. So I need to pull it straight back enough to get the pulley back on. I thought I had all the lines removed from the hydraulic pumps, but I must not. The engine moves back a little, but not enough. Any thoughts on what I missed? Are there some underneath the hydraulic pumps? BTW, I took your advice and I wired the tension rod to the engine so it won't spring back. Seems to be working fine so far. Thanks
